Some on this group just never have contact with the universe of Harbor Freight coupons existing in the wild.
Sure, you can sign-up for their monthly advertising circular or email newsletter and harvest SOME of the coupons, but you can't experience the universe of possibilities those interacting with the rest of society can (AAA magazine, Parade, the Sunday paper, Car & Driver magazine, etc.). I just discovered various entrepreneurs have made it now possible to survey the whole HF ad galaxy!
Ebay.
Yep, what these enterprising folks have done is clip the coupon and put it up for bids on the popular auction site.
For example, one current coupon offers 20% off any single item AND a free flashlight for a piddly $3.00!
If you want to get drowned, use the Google search term of "coupon+harbor+freight".
If you're looking only for the 20% deal, add "20%" to your search term; if you want only the free flashlight, add "flashlight"; and so on.